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A study of enzyme‐catalyzed product deposition on planar gold electrodes using electrical impedance measurement
Author(s) -
Athey Dale,
Ball Mark,
McNeil Calum J.,
Armstrong Ron D.
Publication year - 1995
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140070313
Subject(s) - biotinylation , electrode , avidin , capacitance , substrate (aquarium) , materials science , chemistry , analytical chemistry (journal) , chromatography , biochemistry , oceanography , geology
An electrical impedance based specific binding assay which utilizes the avidin‐biotin interaction is described. The specific binding of a biotinylated enzyme label, alkaline phosphatase, is determined by monitoring the change in capacitance of an avidin‐coated planar gold electrode. The enzyme label alkaline phosphatase converts the substrate 5‐bromo‐4‐chloro‐3‐indolyl phosphate to an insoluble dimeric product which adheres specifically to the surface of the gold electrode and causes a maximum decrease in electrode capacitance of 55%. This capacitance change is directly related to the amount of biotinylated enzyme bound to the surface of the electrode. Electrical impedance analysis has been used to characterize the surface effects on the electrode.